java下properties属性文件操作

package cn.stat.p1.file;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Properties;
import java.util.Set;

public class proc {

/**
* @param args
* @throws IOException
*/
public static void main(String[] args) throws IOException {
// TODO Auto-generated method stub
//创建文件对像
File file=new File("info.txt");

//判断文件是否存在
if(!file.exists())
{
file.createNewFile();
}
//创建文件读取对像
FileReader fr=new FileReader(file);

//创建属性集合
Properties pt=new Properties();
//读取属性集合
pt.load(fr);

//输出到控制台
pt.list(System.out);

//更改
pt.setProperty("lisi", "99");
//创建文件写入对像
FileWriter fw=new FileWriter(file);
//将此 Properties 表中的属性列表写入对像
pt.store(fw,"");

pt.list(System.out);
fr.close();

}

public static void cl2() throws FileNotFoundException, IOException {
Properties pt=new Properties();

FileInputStream fis=new FileInputStream("info.txt");

pt.load(fis);

pt.list(System.out);
}

public static void cl() throws FileNotFoundException, IOException {
Properties pt=new Properties();
pt.setProperty("zhangsan","22");
pt.setProperty("lisi","332");
pt.setProperty("xiaoli","452");
pt.setProperty("nini","112");

FileOutputStream fos=new FileOutputStream("info.txt");

pt.store(fos,"names");

fos.close();

pt.list(System.out);

Set<String> st=pt.stringPropertyNames();

for(String ss : st)
{
String value=pt.getProperty(ss);
System.out.println(ss+" "+value);
}
}

}